The effect of solubilized homologous zona pellucida on the human acrosome reaction, sperm-zona binding and motion characteristics of capacitated human spermatozoa

[摘要] ENGLISH ABSTRACT:CHAPTER 1 provides literature based background information to emphasize the use of a sequential,multistep diagnostic schedule for couples in an assisted reproductive program as well as the clinicalimportance of sperm morphology as recorded by strict criteria during the diagnostic approach of theinfertile couple. Furthermore, the chapter includes evidence underlining the growing need for theimplementation of the physiologically induced acrosome reaction as an important contribution to theassisted reproductive program. The zona pellucida-induced acrosome reaction (ZIAR), sperm-zonainteraction as well as computer-assisted semen analyses were investigated. CHAPTER 2 providesdetailed experimental protocols of the materials and methods used in the study. CHAPTERS 3-6 eachrepresent a separate study that was prepared as a scientific paper and encompass the experimentalresearch undertaken in the reproductive biology research laboratory at Tygerberg Hospital to addressimportant aspects of human acrosome processes. In the first study, we aimed to evaluate theregulatory role of the Gi-like protein during the AR of normal sperm donors and the role of intactacrosomes during sperm-zona binding. It seems that pertussis toxin-sensitive Gi-like protein in humanspermatozoa plays an important regulatory role in the ZIAR and this underlines the importance ofintact acrosomes during sperm-zona binding. In the second study, we aimed to evaluate therelationship between the ZIAR and the percentage normal spermatozoa as well as the sperm-ZPbinding potential among men referred for a routine semen analysis. ZIAR testing should become partof the second level of male fertility investigations, i.e., sperm functional testing, since 15% of theandrology referrals revealed an impaired AR response to solubilized ZP. In the third study, we aimedto evaluate the possible relationships between the sperm morphology, the acrosome responsiveness tosolubulized human ZP and the sperm-zona binding potential among consecutive andrology referralsand randomly selected IVF cases. ZIAR results provide further information regarding dysfunctionalsperm and can be used as an additional diagnostic test since the results predicted fertilization failureduring IVF treatment. In the fourth study, we aimed to evaluate changes in the sperm motioncharacteristics and the occurrence of hyperactivated motility after exposure to ZP among andrologyreferrals. Solubilized human ZP induces hyperactivated motility among sperm populations that havebeen capacitated under laboratory conditions. Capacitated spermatozoa have an elevated percentagehyperactivated cells that correlate with the percentage normal spermatozoa in the ejaculate.CHAPTER 7, the general discussion, is brief and concise to avoid unnecessary repetition, underlinesthe validity of a sequential, multistep diagnostic approach and concludes with the recommendation thatthe ZIAR should form part of the diagnostic tools in the assisted reproductive program.

[发布机构] Stellenbosch University